Examples of conventional wheel speed sensors of this type are given below.
Patent Literature 1 (Japanese Unexamined Patent Application Publication No. 2006-322875) discloses a technique of securely attaching a bent wire to a resin sensor unit while avoiding increase of the number of parts.
More particularly, an IC is placed first within a case housing in reference to a side wall of the case housing. The wire and an IC lead are drawn out from the case housing along an axis of the sensor unit and covered with a first resin molding part. The sensor unit is placed to a mold, taking into account an angle of the side wall. Resin is charged into the mold with the wire being bent at a right angle to the sensor unit, thereby to resin mold an outer peripheral area of the sensor unit. This provides a second resin molding part while forming a bent part for securing the bent wire.
Patent Literature 1 describes that such a manufacturing method allows placement of the IC on a predetermined position within the case housing, and adjustment of the direction of drawing the wire from the case housing. In addition, the wire is bent and fixed with the bent part formed by resin molding, which dispenses with any separate part, and thus firmly fixed to enhance reliability as a rotation detection device for a vehicle.
Patent Literature 2 (Japanese Unexamined Patent Application Publication No. 2004-257867) discloses a resin integrally molded rotation speed sensor for preventing an electric wire or a lead terminal from being positioned on one side inside a sensor unit or being exposed to the outside.
According to the above technique, the electric wire or the lead terminal connected to a rotation speed detection device is inserted into the rotation speed sensor to be limited in position. While a position limiting element for limiting the position of the electric wire or the lead terminal is held from the outside, the rotation speed detection device and other elements are integrally resin molded. Such a technique prevents molding pressure from being applied to a connecting point between the rotation speed detection device and the electric wire or the lead terminal, thereby to avoid disconnection and to achieve a uniformed thickness of the resin. Such an arrangement can satisfy various needs for changing the outer configuration.